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target-arm: A64: Add floating-point<->fixed-point instructions 

This patch adds emulation for the instruction group labeled
"Floating-point <-> fixed-point conversions" in the ARM ARM.

Namely this includes the instructions SCVTF, UCVTF, FCVTZS, FCVTZU
(scalar, fixed-point).

Signed-off-by: Alexander Graf <agraf@suse.de>
[WN: Commit message tweak, rebased, updated to new infrastructure.
 Applied bug fixes from Michael Matz and Janne Grunau.]
Signed-off-by: Will Newton <will.newton@linaro.org>
[PMM: significant cleanup]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Alexander Graf 2014-01-07 17:19:14 +00:00 committed by Peter Maydell
parent 3c6a074a08
commit 52a1f6a3ab
3 changed files with 200 additions and 1 deletions
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13
target-arm/helper.c
View File

@ -4035,6 +4035,19 @@ VFP_CONV_FIX_A64(uq, s, 32, 64, uint64)
#undef VFP_CONV_FIX_FLOAT
#undef VFP_CONV_FLOAT_FIX_ROUND
/* Set the current fp rounding mode and return the old one.
* The argument is a softfloat float_round_ value.
*/
uint32_t HELPER(set_rmode)(uint32_t rmode, CPUARMState *env)
{
float_status *fp_status = &env->vfp.fp_status;
uint32_t prev_rmode = get_float_rounding_mode(fp_status);
set_float_rounding_mode(rmode, fp_status);
return prev_rmode;
}
/* Half precision conversions. */
static float32 do_fcvt_f16_to_f32(uint32_t a, CPUARMState *env, float_status *s)
{

2
target-arm/helper.h
View File

@ -148,6 +148,8 @@ DEF_HELPER_3(vfp_uhtod, f64, i64, i32, ptr)
DEF_HELPER_3(vfp_ultod, f64, i64, i32, ptr)
DEF_HELPER_3(vfp_uqtod, f64, i64, i32, ptr)
DEF_HELPER_FLAGS_2(set_rmode, TCG_CALL_NO_RWG, i32, i32, env)
DEF_HELPER_2(vfp_fcvt_f16_to_f32, f32, i32, env)
DEF_HELPER_2(vfp_fcvt_f32_to_f16, i32, f32, env)
DEF_HELPER_2(neon_fcvt_f16_to_f32, f32, i32, env)

186
target-arm/translate-a64.c
View File

@ -3186,6 +3186,34 @@ static void disas_data_proc_reg(DisasContext *s, uint32_t insn)
}
}
/* Convert ARM rounding mode to softfloat */
static inline int arm_rmode_to_sf(int rmode)
{
switch (rmode) {
case FPROUNDING_TIEAWAY:
rmode = float_round_ties_away;
break;
case FPROUNDING_ODD:
/* FIXME: add support for TIEAWAY and ODD */
qemu_log_mask(LOG_UNIMP, "arm: unimplemented rounding mode: %d\n",
rmode);
case FPROUNDING_TIEEVEN:
default:
rmode = float_round_nearest_even;
break;
case FPROUNDING_POSINF:
rmode = float_round_up;
break;
case FPROUNDING_NEGINF:
rmode = float_round_down;
break;
case FPROUNDING_ZERO:
rmode = float_round_to_zero;
break;
}
return rmode;
}
static void handle_fp_compare(DisasContext *s, bool is_double,
unsigned int rn, unsigned int rm,
bool cmp_with_zero, bool signal_all_nans)
@ -3651,6 +3679,132 @@ static void disas_fp_imm(DisasContext *s, uint32_t insn)
tcg_temp_free_i64(tcg_res);
}
/* Handle floating point <=> fixed point conversions. Note that we can
* also deal with fp <=> integer conversions as a special case (scale == 64)
* OPTME: consider handling that special case specially or at least skipping
* the call to scalbn in the helpers for zero shifts.
*/
static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode,
bool itof, int rmode, int scale, int sf, int type)
{
bool is_signed = !(opcode & 1);
bool is_double = type;
TCGv_ptr tcg_fpstatus;
TCGv_i32 tcg_shift;
tcg_fpstatus = get_fpstatus_ptr();
tcg_shift = tcg_const_i32(64 - scale);
if (itof) {
TCGv_i64 tcg_int = cpu_reg(s, rn);
if (!sf) {
TCGv_i64 tcg_extend = new_tmp_a64(s);
if (is_signed) {
tcg_gen_ext32s_i64(tcg_extend, tcg_int);
} else {
tcg_gen_ext32u_i64(tcg_extend, tcg_int);
}
tcg_int = tcg_extend;
}
if (is_double) {
TCGv_i64 tcg_double = tcg_temp_new_i64();
if (is_signed) {
gen_helper_vfp_sqtod(tcg_double, tcg_int,
tcg_shift, tcg_fpstatus);
} else {
gen_helper_vfp_uqtod(tcg_double, tcg_int,
tcg_shift, tcg_fpstatus);
}
write_fp_dreg(s, rd, tcg_double);
tcg_temp_free_i64(tcg_double);
} else {
TCGv_i32 tcg_single = tcg_temp_new_i32();
if (is_signed) {
gen_helper_vfp_sqtos(tcg_single, tcg_int,
tcg_shift, tcg_fpstatus);
} else {
gen_helper_vfp_uqtos(tcg_single, tcg_int,
tcg_shift, tcg_fpstatus);
}
write_fp_sreg(s, rd, tcg_single);
tcg_temp_free_i32(tcg_single);
}
} else {
TCGv_i64 tcg_int = cpu_reg(s, rd);
TCGv_i32 tcg_rmode;
if (extract32(opcode, 2, 1)) {
/* There are too many rounding modes to all fit into rmode,
* so FCVTA[US] is a special case.
*/
rmode = FPROUNDING_TIEAWAY;
}
tcg_rmode = tcg_const_i32(arm_rmode_to_sf(rmode));
gen_helper_set_rmode(tcg_rmode, tcg_rmode, cpu_env);
if (is_double) {
TCGv_i64 tcg_double = read_fp_dreg(s, rn);
if (is_signed) {
if (!sf) {
gen_helper_vfp_tosld(tcg_int, tcg_double,
tcg_shift, tcg_fpstatus);
} else {
gen_helper_vfp_tosqd(tcg_int, tcg_double,
tcg_shift, tcg_fpstatus);
}
} else {
if (!sf) {
gen_helper_vfp_tould(tcg_int, tcg_double,
tcg_shift, tcg_fpstatus);
} else {
gen_helper_vfp_touqd(tcg_int, tcg_double,
tcg_shift, tcg_fpstatus);
}
}
tcg_temp_free_i64(tcg_double);
} else {
TCGv_i32 tcg_single = read_fp_sreg(s, rn);
if (sf) {
if (is_signed) {
gen_helper_vfp_tosqs(tcg_int, tcg_single,
tcg_shift, tcg_fpstatus);
} else {
gen_helper_vfp_touqs(tcg_int, tcg_single,
tcg_shift, tcg_fpstatus);
}
} else {
TCGv_i32 tcg_dest = tcg_temp_new_i32();
if (is_signed) {
gen_helper_vfp_tosls(tcg_dest, tcg_single,
tcg_shift, tcg_fpstatus);
} else {
gen_helper_vfp_touls(tcg_dest, tcg_single,
tcg_shift, tcg_fpstatus);
}
tcg_gen_extu_i32_i64(tcg_int, tcg_dest);
tcg_temp_free_i32(tcg_dest);
}
tcg_temp_free_i32(tcg_single);
}
gen_helper_set_rmode(tcg_rmode, tcg_rmode, cpu_env);
tcg_temp_free_i32(tcg_rmode);
if (!sf) {
tcg_gen_ext32u_i64(tcg_int, tcg_int);
}
}
tcg_temp_free_ptr(tcg_fpstatus);
tcg_temp_free_i32(tcg_shift);
}
/* C3.6.29 Floating point <-> fixed point conversions
* 31 30 29 28 24 23 22 21 20 19 18 16 15 10 9 5 4 0
* +----+---+---+-----------+------+---+-------+--------+-------+------+------+
@ -3659,7 +3813,37 @@ static void disas_fp_imm(DisasContext *s, uint32_t insn)
*/
static void disas_fp_fixed_conv(DisasContext *s, uint32_t insn)
{
unsupported_encoding(s, insn);
int rd = extract32(insn, 0, 5);
int rn = extract32(insn, 5, 5);
int scale = extract32(insn, 10, 6);
int opcode = extract32(insn, 16, 3);
int rmode = extract32(insn, 19, 2);
int type = extract32(insn, 22, 2);
bool sbit = extract32(insn, 29, 1);
bool sf = extract32(insn, 31, 1);
bool itof;
if (sbit || (type > 1)
|| (!sf && scale < 32)) {
unallocated_encoding(s);
return;
}
switch ((rmode << 3) | opcode) {
case 0x2: /* SCVTF */
case 0x3: /* UCVTF */
itof = true;
break;
case 0x18: /* FCVTZS */
case 0x19: /* FCVTZU */
itof = false;
break;
default:
unallocated_encoding(s);
return;
}
handle_fpfpcvt(s, rd, rn, opcode, itof, FPROUNDING_ZERO, scale, sf, type);
}
static void handle_fmov(DisasContext *s, int rd, int rn, int type, bool itof)